const path = require("path"); // node内置核心模块，用来设置路径。
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CssMinimizerPlugin = require("css-minimizer-webpack-plugin");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const ESLintPlugin = require("eslint-webpack-plugin");
const CopyWebpackPlugin = require("copy-webpack-plugin");

module.exports = {
  //入口文件
  entry: path.resolve(__dirname, "../src/index.js"),
  //出口文件
  output: {
    path: path.resolve(__dirname, "../build"),
    filename: "./js/main.js",
  },
  
  //模块配置，配置loader
  module: {
    rules: [
      {
        /* 
          test:后边配置的是一个正则表达式,用来匹配文件名是否符合当前loader的条件
        */
        test: /\.css$/i,
        // use: ["style-loader", "css-loader"],
        use: [MiniCssExtractPlugin.loader, "css-loader"],
      },
      {
        test: /\.less$/i,
        // use: [
        //     //use中loader加载是有顺序的，先下后上，注意有的loader需要按照顺序书写
        //     "style-loader",
        //     'css-loader',
        //     'less-loader'
        // ]
        use: [MiniCssExtractPlugin.loader, "css-loader", "less-loader"],
      },
      {
        test: /\.(png|jpg|gif|webp)$/,
        //asset 在导出一个 data URI 和发送一个单独的文件之间自动选择。代替之前的url-loader和file-loader
        type: "asset",
        parser: {
          dataUrlCondition: {
            maxSize: 30 * 1024, // 小于30kb以下的图片会被打包成base64格式
          },
        },
        generator: {
          filename: "images/[name][ext]",
        },
      } /* {
        test: /\.(htm|html)$/i,
        use: {
            loader: 'html-loader'
        }
    }, */,
    ],
  },

  //优化的配置
  optimization: {
    minimizer: [new CssMinimizerPlugin()],
  },

  //插件配置
  plugins: [
    new MiniCssExtractPlugin({
      //输出独立文件的文件名
      filename: "./css/main.css",
    }),
    new HtmlWebpackPlugin({
      filename: "index.html",
      template: path.resolve(__dirname, "../public/index.html"), //以某某为起始点开始进行打包
      minify: {
        collapseWhitespace: true,
        keepClosingSlash: true,
        removeComments: true,
        removeRedundantAttributes: true,
        removeScriptTypeAttributes: true,
        removeStyleLinkTypeAttributes: true,
        useShortDoctype: true,
      },
    }),
    new ESLintPlugin({ fix: true }),
    new CopyWebpackPlugin({
      patterns: [
        {
          from: path.resolve(__dirname, "../public"),
          to: "public",
          //配置复制时忽略的文件
          globOptions: {
            ignore: ["**/index.html"],
          },
        },],
    }),  ],

  //打包模式
  mode: "production", //还有development模式
};
